Mixture Screw/Colortune Question...82XJ650

I need to get this right. I don't see a color change in the Colortune plug. Valves are in spec. Carbs sync'd. Bike starts and idles at 1050rpms. Mixture screws set at 3 turns out. Yics tool installed. Colortune plug installed. As I turn the mixture screw out the rpms slowly start to increase. Is it at this point that chamber is rich and I should turn the screw back in until the bike returns to normal idle? Do this for all four then sync the carbs again? Then plug chop and make adjustments as needed? Thanks.

Gary

 

No color change on any cylinder?

What color were you seeing?

 

To prove that I don't know it all, does the YICS tool need to be installed when adjusting the idle mixture? Since I don't know the answer to this question for sure, I theorize that with the YICS tool installed for this purpose, that it doesn't matter to the engine. But I could be wrong.

 

According to Yamaha the answer is yes.

Yamaha's procedure for adjusting idle mixtures involved the use of an EGA, with YICS blocked; and the ColorTune is our "visual substitute" for the EGA.

 

BigFitz,

I'm seeing powder blue. Pipes yellowing at top bend and plug electrodes still white at 3 turns out. Thanks.

Gary

 

You're LEAN. If turning the pilots out isn't doing anything then your pilot circuits are still plugged up (or float levels horribly off.)

Or you have a massive vacuum leak somewhere (or YICS isn't properly blocked, causing said vacuum leak.)

 

ok. thanks.

Gary

 

Powder Blue is only Ideal for IDLE.
You must add additional (Supplemental Richness) just beyond the Blue to prevent hesitation.

The Supplemental Richness provides the Fuel needed to maintain combustion(s) during the BRIEF introduction of Fresh Air which precedes the Main Jet Supply.

The Supplemental Richness involves turning the Mixture Screw OUT past the Blue about the width of a Nickel.

The duration of Fresh Air preceding the Main Jet Supply is less than a second, but if not sufficiently Fueled, causes the Plant to hesitate.

 

Thanks.

Gary

 

Thank you Fitz for the answer to my question.